In recent years, wireless power supply systems capable of wirelessly supplying power from a power supply side to a power receiving side without a wire (cable) connecting the power supply side and the power receiving side have been used for various purposes.
For example, a wireless power supply system has been used to supply power for charging a battery mounted in a vehicle such as an electric vehicle (EV) or a hybrid vehicle (HV) or a battery provided in a consumer appliance such as a household electrical appliance (for example, see Patent Document 1).
In such a wireless power supply system, it is necessary to appropriately set a relative positional relationship between a power supply coil (primary side coil) provided on a power supply side and a power receiving coil (secondary side coil) provided on a power receiving side so as to efficiently transmit power in a wireless manner. For example, when the battery provided in the vehicle such as the aforementioned EV or HV is charged, it is necessary to appropriately set a relative position between the power receiving coil provided in the vehicle and the power supply coil according to a stop position of the vehicle.
Patent Document 2 discloses a wireless power supply system which is provided with a relay device held in a vertically movable hold unit between the power supply coil and the power receiving coil and which prevents power transmission efficiency from being degraded due to relative position deviation between a power supply coil and a power receiving coil by moving the relay device according to a relative positions of the power supply coil and the power receiving coil. In addition, Patent Document 2 also discloses technology which is provided with a foreign object remover for removing a foreign object around a power transmission path for power transfer and which avoids a bad influence on power transfer due to the foreign object different from a power supply target.
In addition, Patent Document 3 discloses a power reception support apparatus capable of performing appropriate support in terms of correction of a position of a vehicle when power from the power supply apparatus is received. The above-described power reception support apparatus includes a power reception efficiency specifying unit configured to specify power reception efficiency of a power receiving unit at a current position of a vehicle and a support unit configured to determine whether power reception efficiency can become greater than or equal to a threshold value by adjusting a vehicle height of the vehicle when the power reception efficiency specified by the power reception efficiency specifying unit is less than the threshold value and to perform support for adjusting the height of the vehicle when it is determined that the power reception efficiency can become greater than or equal to the threshold value.
In addition, Patent Document 4 discloses a resonance type wireless power supply system for a vehicle capable of efficiently supplying power from a power supply side to a power receiving side using a vehicle height adjustment function when wireless power supply is performed for an electric motor vehicle having a vehicle height adjustment function. The above-described resonance type wireless power supply system for the vehicle includes a power supply facility having a high-frequency power supply and a primary side resonance coil and an electric motor vehicle equipped with a power receiving facility having a secondary side resonance coil configured to receive power from the primary side resonance coil and a vehicle height adjustment apparatus.
The power receiving facility includes a rectifier configured to rectify power received by the secondary side resonance coil, a secondary battery to which power rectified by the rectifier is supplied, and a control apparatus configured to perform impedance adjustment of a resonance system including the primary side resonance coil and the secondary side resonance coil using the vehicle height adjustment apparatus when the secondary battery is charged.
In addition, Patent Document 5 discloses a parking support apparatus that is provided in a vehicle capable of storing power by wirelessly receiving the power from an external power transmission unit through a power receiving unit, that enables a driver to conveniently perform charging, and that reduces a feeling of complexity of a charging operation. The above-described parking support apparatus includes a vehicle control unit configured to control the vehicle so as to adjust positions of the power transmitting unit and the power receiving unit based on a power reception situation of the power receiving unit and a height sensor for sensing a change in the height of the vehicle. The vehicle control unit performs position alignment based on an output of the height sensor and the power reception situation using a relationship between a power reception situation and a distance between the power transmitting unit and the power receiving unit predetermined according to the output of the height sensor.
In addition, Patent Document 6 discloses technology for filling a space between the power transmitting unit and the power receiving unit with a bag and preventing the intrusion of a foreign object into the aforementioned space. Further, Patent Document 7 discloses technology for detecting and removing a foreign object intruding between the power transmitting coil and the power receiving coil.